1. Field of the Invention
This invention relates to an engine mount device through which a power unit is mounted on a support body, and more particularly to an engine mount device of the fluid-filled type for elastically supporting an automotive internal combustion engine on a vehicle body.
2. Description of the Prior Art
It is well known in the art that fluid-filled engine mount devices are used to elastically support an automotive internal combustion engine on a vehicle body. The engine mount device is composed of a rubber block which is formed with a central cavity and securely interposed between upper and lower base plate members which are respectively connected to the engine side and to the vehicle body side. A partition plate member having an orifice is disposed to define a fluid chamber to be filled with a fluid and an auxiliary chamber which communicates through the orifice with the fluid chamber, so that the fluid is capable of flowing from the fluid chamber to the auxiliary chamber and vice versa in response to the contraction and expansion of the rubber block.
Additionally, in such an engine mount device, it has been proposed that the partition plate member is arranged to be movable to absorb high frequency vibration applied from the engine to the engine mount device. However, even by the thus arranged engine mount device, it is difficult to effectively absorb the high frequency vibration, for example, during vehicle cruising where both high and low frequency vibrations are applied to the engine mount device. Because, the fluid movement due to the low frequency vibration urges the partition plate member to contact with the upper base plate member and its vicinity, so that the high frequency vibration applied the engine mount device is transmitted via the partition plate member to the vehicle body side.